33 ° 
Wager . — On the Structure and 
The sections observed and described above were stained 
in osmic acid for twenty-four hours and mounted in dilute 
glycerine. 
In the earlier stages, before the formation of the oosphere 
and just after its delimitation, a number of small, bright, 
refracting spheres were observed. These stained light yellow 
in osmic acid, and were probably small oil-globules in process 
of formation. 
The antheridium is sometimes observed cut transversely in 
an oosphere. The dense protoplasm contained in it then 
nearly always presents the appearance of a crescent, owing 
to the protoplasm being more on one side of the tube than 
the other, and this is what Dangeard has probably mistaken 
for oil-crescents, and which I was inclined at first also to 
regard as due to the presence of oil. 
Fertilization. 
While the changes already described have been taking 
place in the oogonium, the nuclei of the antheridium have 
been undergoing division, and the number of nuclei at this 
stage is also now, so far as can be observed, about double the 
number at the beginning. The fertilizing tube has grown, 
and has at this stage pushed its way through the periplasm 
into the gonoplasm. A single nucleus and a small quantity 
of densely stained protoplasm passes from the antheridium 
into it down the side of the fertilizing tube (Fig. 11) to the 
apex (Figs. 12 and 13). The remainder of the tube is 
occupied by a thin lining layer of protoplasm and a large 
vacuole (Fig. 13). 
The fertilizing tube now grows towards the centre of the 
young oosphere, around which a limiting membrane has not 
yet been formed. As it grows, the dense mass of protoplasm 
becomes reduced in amount, being used up probably to form 
the new growing wall. The apex of the fertilizing tube 
expands considerably, and it looks just as if this took place 
